Clear Skies? Yes, Please!
By Calvin L. Chrisman
I usually end this column wishing you clear skies. Unfortunately for 2013, clear skies have been in short supply. Yes, we need the rain, but we have had too much of a good thing. Through the end of June, the 40 inches of rain for six months exceeds four of the last eight years. As of this writing, July has had over fifteen inches of rain, making it the rainiest July in almost a century. We should hope that the rain slows down and allows us to view some of the special events in the August sky; most especially the Perseids Meteor Shower.
This year, the waxing crescent Moon will set before midnight, allowing excellent dark skies for observing this reliable meteor shower. Under dark skies, peak activity is expected to be between 50 to 100 meteors per hour. Viewing will be best between midnight and dawn on the nights of August 11-12 and August 12-13. At those times, the Earth’s atmosphere will be pointed most directly into the debris stream left by Comet 109P/Swift-Tuttle. These small bits of rock will be slamming into the atmosphere at about 37 miles per second creating a stream of ionized gas for your viewing pleasure.
You do not need to look toward the constellation Perseus, which will rise in the northeast around 10:00 p.m. The meteors will be visible across the entire sky and their tails will point in the direction of Perseus. Go out around midnight, lie back in a lawn chair with a blanket or sleeping bag and some bug repellant and watch a dark part of the sky. If you have ever wondered, a meteor is the streak of light you see crossing the sky. If it survives a trip through the atmosphere and makes it to the Earth, it is then referred to as a meteorite. The light trail that you see is not the space rock (aka meteoroid) burning up; it is a trail of ionized gases caused by the shock wave of the rock passing into the atmosphere at high speed.
If you are interested in planet watching, Venus and Saturn are in the western sky around dusk and Jupiter and Mars are in the eastern sky shortly before dawn. Jupiter will rise at about 3:30 a.m. at the beginning of the month with Mars close behind. Both planets will rise earlier as the month progresses and will be visible longer as sunrise comes later.
Here’s hoping that the clouds cooperate and give us an opportunity to watch the show that the Perseids have in store for us.
Visit Calvin Chrisman’s website at: www.DillKnobObservatory.net for links to astronomical sites of interest and past articles.